Field of the Invention
The present invention relates to a liquid crystal display (LCD) device, and more particularly, to an LCD device and a method of manufacturing the same, which reduce a capacitance deviation between pixels without any change in a viewing angle and a transmittance.
Discussion of the Related Art
With the advance of various portable electronic devices such as mobile communication terminals, smart phones, tablet computers, notebook computers, etc., the demand for flat panel display (FPD) devices applicable to the portable electronic devices is increasing.
Liquid crystal display (LCD) devices, plasma display panels (PDPs), field emission display (FED) devices, organic light emitting display devices, etc. have been developed as the FPD devices.
In such FPD devices, applications of the LCD devices have expanded because the LCD devices can be easily manufactured due to the advance of manufacturing technology, ease of implementation, low power consumption, a high-quality image, and a large screen.
FIG. 1 is a diagram illustrating a pixel structure of a related art LCD device. FIG. 1 illustrates a portion of a plurality of pixels which are formed in a liquid crystal panel, and illustrates a pixel structure of a thin film transistor (TFT) array substrate (a lower substrate) in an in-plane switching (IPS) mode. In FIG. 1, a color filter array substrate (an upper substrate), a backlight unit, and a driving circuit unit are not illustrated.
Referring to FIG. 1, a plurality of pixels are formed on the TFT array substrate of the liquid crystal panel, and are defined by a plurality of gate lines 10 and a plurality of data lines 20 which are formed to intersect.
A TFT 30 is formed in each of a plurality of areas defined by intersections between the gate lines 10 and the data lines 20.
The TFT 30 is formed in a bottom gate type, and includes a gate electrode G of which an area extends from the gate line 10, a source electrode S which extends from the data line 20, an active layer formed of a semiconductor material, and a drain electrode D.
A pixel electrode 40 for supplying a data voltage based on image data input from the outside is formed in each of the plurality of pixels, and a common electrode 50 is formed on the pixel electrode 40.
The drain electrode D of the TFT 30 is connected to the pixel electrode 40 through a contact hole. In order to prevent a loss of an aperture ratio of each pixel, the contact hole is formed in a storage capacitor (Cst) area. The common electrode 50 is patterned to have a finger shape in each pixel, and is formed in common in all the pixels.
A finger pattern of the common electrode 50 is formed to be inclined at a certain angle, and the pixel electrode 40 is formed to be inclined at a substantially same angle as that of the finger pattern.
The pixels of the related art LCD device illustrated in FIG. 1 are formed in a 2-domain structure where upper and lower pixels are formed in different forms. Therefore, in comparison with a 1-domain structure, the 2-domain structure improves a viewing angle, and solves a drawback of a color shift.
However, the data lines are alternately formed to be inclined at a certain angle. Therefore, a profile of each pixel is formed in a trapezoid shape, and two pixels which are adjacent in a horizontal direction are formed in a connected form.
As described above, when the pixels are formed in a trapezoid shape, in a manufacturing process, a plurality of metal layers may be formed to be distorted without properly overlapping each other.
Therefore, areas in which the metal layers overlap each other differ in each pixel, and thus, capacitances of the pixels differ. For this reason, line dim in a height direction and a width direction, and flicker may occur, causing the degradation in a quality of an image.